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turning an epi 100 into a bass module

Frode365

Frode365

Member
I have been thinking lately that a 3rd or maybe even 4th EPI 100 in my listening space would be so much more aesthetically appealing than a prefabbed sub on the floor. I am not a mastermind of what it would take to make it make sense running with a set of 100’s as far as getting the frequencies correct. But I am always down for a project, especially an upcycle/recycle project. Any thoughts on the subject? I do run a wiim with sub output and control in that room, so could use an amp and I believe control the creative settings from the wiim. maybe a plate amp makes more sense? but already dealing with a pretty small enclosure to begin with. Does adding a passive radiator make sense? Just thinking out loud here
 
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If you use the EPI 100 woofer in a larger enclosure with a passive radiator, it can indeed make a good bass module. In fact, my rear subs in my home listening system, are EPI 8", with a passive radiator, in about a 2 cubic foot enclosure, each.

Minimum box volume that seems to work well with an EPI 8" woofer with a passive radiator, is about 1.7 cubic feet. I'd use probably a 10" or 12" passive radiator with it. That said, its performance is pretty phenomenal. F3 is about 22Hz!

If you need the small size of the EPI 100 enclosure, keep it sealed. A passive radiator won't really give flat bass response in that small of an enclosure.

Regards,
Gordon.
 
Thank you Gordon, My first thought is to utilize the EPI 100 enclosure and I think the look would be best, and definitely could use two of them it that helps, neatly tucked into the corners behind the EPI 100 mains.. Is there a way to get more/lower end bass out of that setup or am I looking at essentially adding more of the "same" if you will bass as the mains in that setup?
 
Frode365 said:
My first thought is to utilize the EPI 100 enclosure and I think the look would be best, and definitely could use two of them it that helps, neatly tucked into the corners behind the EPI 100 mains.. Is there a way to get more/lower end bass out of that setup or am I looking at essentially adding more of the "same" if you will bass as the mains in that setup?
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if you cut the backs off of the pair of 100's and glue them together, back-to-back, you'll be doubling the enclosure volume. The result would be a nice piece of walnut veneered furniture with a woofer on one side and the passive on the other. The woofer and passive don't need to be pointing towards the listener, they would be firing to the side.
 
my listening space is small, trying to avoid anything that large. On most music the M100's aren't falling short in the room (I do mostly run them with a GFA-555 so no shortage of power). I am just constantly looking for things to keep my brain and hands busy, so this is something that can be started and evolve with time. My buddy has a small square powered sub that I believe is 8" woofers that is pretty impressive, so there must be a way to get some bass out of a small enclosure, just beyond my scope of knowledge at this point.
 
Thank you for the suggestions, I have amplifiers around that could drive it.. I haven't gotten that deep, but I do have some Fosi V3 monoblocks around that could probably get the job done.

Looks like "staff recommendations" call for a 0.5ft³ sealed enclosure. The M100 I believe is closer to 0.75ft³. would you suggest decreasing the inner size of the M100 cabinet (add a wall essentially within the cabinet) or just leave it?
 
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Just leave it, it will go deeper in a bigger box, keep the stuffing away from the woofer.
Do you have any EQ, DSP so that you can boost say around 35 Hz as needed?
Fosi V3 should be excellent.
 
Frode365 said:
Thank you for the suggestions, I have amplifiers around that could drive it.. I haven't gotten that deep, but I do have some Fosi V3 monoblocks around that could probably get the job done.

Looks like "staff recommendations" call for a 0.5ft³ sealed enclosure. The M100 I believe is closer to 0.75ft³. would you suggest decreasing the inner size of the M100 cabinet (add a wall essentially within the cabinet) or just leave it?
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I don't know where 0.5 cubic feet came from- but that's ABSOLUTELY NOT what my simulations have indicated.

For the 005 woofer that's in the majority of EPI cabinets (including the 100), the specs make for an sealed Butterworth alignment (Qtc= 0.707) with about 0.99 cubic feet. In 0.75 cubic feet, the Q is about 0.77. That's already peaking a little, but not bad (less than one dB of ripple). And those are with simulating the cabinet absolutely filled with fiberglass insulation.

I'd definitely never try to decrease the internal volume of the M100. In fact, the primary reason the M150 sounded better than the M100, was the larger cabinet (1.4 cubic feet, roughly). That's a Q of about 0.65- better damping.

Regards,
Gordon.
 
Pete B said:
Might you want to replace the woofer with a real sub woofer?

Do you have a power amp for it already or how do you plan to drive it?
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That has more excursion- but not a LOT more excursion. 10.5mm X-max, as opposed to about 7mm for the stock 005. That's about 3dB more output, tops.

The 005s have an almost 0.8" long 4-layer voice coil, stock.

Regards,
Gordon.
 
Pete B said:
Just leave it, it will go deeper in a bigger box, keep the stuffing away from the woofer.
Do you have any EQ, DSP so that you can boost say around 35 Hz as needed?
Fosi V3 should be excellent.
Click to expand...

I have Sub control in the Wiim Ultra which is what I will use to at least test this. I could pretty easily just disconnect the tweeter and see what the EPI woofer in the enclosure does with the fosi v3 run through the sub out on the Ultra, and I can adjust gain and frequency there.
 
GordonW said:
I don't know where 0.5 cubic feet came from- but that's ABSOLUTELY NOT what my simulations have indicated.

For the 005 woofer that's in the majority of EPI cabinets (including the 100), the specs make for an sealed Butterworth alignment (Qtc= 0.707) with about 0.99 cubic feet. In 0.75 cubic feet, the Q is about 0.77. That's already peaking a little, but not bad (less than one dB of ripple). And those are with simulating the cabinet absolutely filled with fiberglass insulation.

I'd definitely never try to decrease the internal volume of the M100. In fact, the primary reason the M150 sounded better than the M100, was the larger cabinet (1.4 cubic feet, roughly). That's a Q of about 0.65- better damping.

Regards,
Gordon.
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I would have my M150's already except the buddy of my son that I am getting them from can't leave base until this Middle east conflict is wrapped up, and we haven't been up to see them either. I am pretty excited to get the 150's and do a full restoration on them. In the meantime, playing with this project will keep me occupied. We will see what kind of time I have to try and mock up one of my 100's to test this weekend.
 
GordonW said:
That has more excursion- but not a LOT more excursion. 10.5mm X-max, as opposed to about 7mm for the stock 005. That's about 3dB more output, tops.

The 005s have an almost 0.8" long 4-layer voice coil, stock.

Regards,
Gordon.
Click to expand...
Just another option that I believe will take significantly more power and EQ as needed.
 
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